摘要
采用吸附等温线测量、荧光探针技术以及沉降实验研究季铵盐在高岭石表面的吸附特性。采用溴百里酚蓝标记分光光度法测量吸附等温线,利用芘荧光探针技术从微观上描述吸附特性和吸附层结构。结果表明:在低浓度范围内(0～1 mmol/L),通过离子交换和静电作用共吸附致吸附量达到完全吸附;随着浓度增加,季铵盐的吸附量与平衡浓度呈直线关系,静电吸附为主;当浓度增大到一定范围内,吸附量增加缓慢,主要以季铵盐分子间疏水缔合作用产生吸附;当浓度达到CMC时,吸附达到平衡。十六烷基三甲基氯化铵(CTAC)和十二烷基三甲基氯化铵(DTAC)的饱和吸附量分别为5.3μmol/m2和5.0μmol/m2,而DTAC临界胶束浓度CMC(13 mmol/L)比CTAC(8mmol/L)的大,当CTAC和DTAC浓度为CMC时,沉降产率达到最大,分别为97.84%和95.39%。
The adsorption characteristics of quaternary ammonium salt on kaolinite were studied using adsorption isotherm, fluorescence probe test and sedimentation test. The adsorption isotherm was measured using spectrophotometric marked by bromothymol blue method. The adsorption layer structure model and adsorption characteristics of quaternary ammonium salts on kaolinite were explained further from microscopic level using pyrene fluorescent probe technology. The results indicate that the cationic surfactant is completely absorbed due to electrostatic interactions and ion exchange on kaolinite surfaces in the low concentration range （0-1 mmol/L）. With the increase of surfactant concentration, the relationship between adsorption and equilibrium concentration is linear, mainly due to electrostatic interactions. With a further increase in surfactant concentration, the adsorption increases slowly due to hydrophobic association of chain-chain interactions. Finally, the adsorption runs to saturation. The saturation adsorbed amounts of CTAC and DTAC are 5.3 ~tmol/m/ and 5.0 pmol/m2, respectively. But the critical micelle concentration（CMC） of DTAC（13 mmol/L） is large than that of CTAC（8 mmol/L）. When the concentrations of CTAC and DTAC reach CMC, Settling yields are 97.84% and 95.39%, respectively. And the adsorption characteristics were verified from macroscopic level by sedimentation test.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2013年第11期4379-4384,共6页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(50974134
51304162)
作者简介
通信作者 蒋昊（1971-），女，湖南湘阴人，高级实验师，从事浮选理论研究；电话：13908477086 E—mail：jianghao-1@126．com
